The invention relates to a hand-lever-actuable pump for spraying liquids, in particular for mounting on bottles or the like, having a pump piston which can be displaced linearly in a pump chamber in the housing and is intended for spraying the liquid out of a mouthpiece nozzle, the pump piston being coupled to the hand lever via a connecting member such that the pivoting movement of the hand lever pulls the piston in the direction of the liquid moving toward the mouthpiece nozzle.
A spray pump of this type is known from U.S. Pat. No. 2,626,185. In the case of this forerunner, the pump piston, including the pump cylinder thereof is located in the bottle. Secured on the bottle neck, the pump housing continues in a pistol-like manner with a trigger-like hand lever mounted in the vertex of the handle and xe2x80x9cbarrelxe2x80x9d. The handle lever is double-armed and, by way of the handle-side arm, acts in an articulated manner on a connecting member which, for its part, is seated in an articulated manner on the piston body. The pump piston is pulled counter to a compression spring which is mounted on the piston body and has its abutment in the housing.
U.S. Pat. No. 2,109,589 proposes allowing the double-armed hand lever to act on the pump cylinder and displacing the latter in a linearly guided manner relative to the fixed pump piston. This requires a line section which extends from the vertical tube and moves along with the movements of the pump cylinder. The articulation location between the pump cylinder and said arm provides a slot into which pins of the pump cylinder project. The hand lever itself is mounted pivotably such that it cannot be displaced.
It is an object of the invention to form a hand-lever-actuable pump of the generic type such that it is structurally straightforward and is reliable to use.
This object is achieved in that, starting from the rear side of the pump piston, the connecting pull member extends parallel to the pump-piston displacement path in the direction of the mouthpiece nozzle. This results in a substantially simplified construction. The connecting pull member and pump piston move in the same direction, i.e. both move linearly. The pump-piston body no longer requires any particular measures in order to carry along the pump piston. Rather, the pump piston is simply subjected to pulling action, and displaced, from the rear side. A straightforward reliable carry-along connection is achieved here in that the rear side has a hook-in slot which is located in the direction of the pump-piston displacement path and is intended for a cross-sectionally non-round drive member of the connecting pull member. As a result, the linear movement or guidance of the pump piston is converted into linear guidance of the connecting pull member. In order, in the case of a pivotable hand-lever version, for the arcuate path of the hand lever and the linear movement of the connecting pull member to be brought into line without constraint in terms of movement, a further configuration is characterized by a slot/pin mounting of the hand lever underneath the liquid-feed channel leading from the pump cylinder to the mouthpiece nozzle. An embodiment of the connecting pull member which is particularly stable during use is achieved if the connecting pull member is configured as an elongate, linearly guided eyelet which encloses the pump cylinder. The eyelet retains the pump piston in a tilt-free manner; it is preferably disposed along the diameter of the cross-section of the pump piston. Furthermore, a structurally advantageous configuration is achieved by a vertical tube which extends upward from the bottle interior and has a liquid-feed channel connecting with it, which channel opens out into the pump chamber in the region of an end wall which is fitted with valves, is directed toward the mouthpiece nozzle and belongs to the pump chamber. This makes it possible to maintain flow paths which run in opposite directions, but shorten the pump. Also advantageous in this context is the measure where the section of the liquid-feed channel which extends coaxially and in extension of the pump chamber is configured as a tubular, resiliently mounted insert element. It is also provided that provided for the resilient mounting of the insert element is a compression spring, the other end of which is supported on the pump-chamber end surface of the pump piston. Such a compression spring, at the same time, forms the restoring spring for the hand lever. It is then proposed that the end surface of the pump piston has a depression into which an end of the insert element which projects freely into the pump chamber can enter. The charge which is to be discharged is delivered by this tubular end in the direction of the mouthpiece nozzle, passing through the annular space-forming surroundings of the insert-element section which has no casing there. A configuration of even independent importance resides in the fact that the valves are fitted on the insert element, to be precise such that an inlet valve and an outlet valve are formed as flexible portions which are integrally formed on the insert element by combination injection molding. The basic body of the insert element itself is of relatively hard configuration, the flexible portions being rubber-like. Such a measure reduces the number of parts and simplifies the assembly. Finally, a further measure is taken, this being embodied in that, when the hand lever is actuated, the pump piston, configured as a double-sleeve piston, passes, by way of the two sleeves, over an air-admission opening, extending to the bottle interior, such that the air-admission opening comes into connection with an air-admission channel which, in the direction of that end of the pump housing which is located opposite the mouthpiece nozzle, extends into the open. In the closed position, the air-admission opening is located, in the cross-sectional plane of the annular space, between the two sleeves. This avoids, by straightforward means, loss of medium, for example if the spray dispenser, which is designed to stand up, falls over and/or is transported in a horizontal position.